1. Field of the Invention
This invention relates to an electrical connector assembly and, more particularly, to a modular electrical connector back shell apparatus having a wire strain relief.
2. Description of the Prior Art
Electrical circuits for many applications including, for example, vehicle electrical wiring applications, are becoming increasingly faster and more complex with the need to accommodate many electrical circuits and components on printed circuit boards or back panels. It is frequently necessary in complex systems to inner-connect circuits contained on back panels to circuits in other locations, for example, by using multi-wiring electrical cabling. As electronic circuits increasingly become faster in operation and more complex, their sensitivity to radio frequency interference and other electrical magnetic radiation increases. Consequently, electrical cables connecting electronic circuits from other locations to back panels or circuit boards are frequently isolated from this interference by casing the cables in a conductive shield or shell.
One form of electrical connectors available for affecting contact between multi-wire cables and electrical circuits contained on printed circuit boards or back panels, is to use a modular electrical connector system. These modular systems allow the assembly of pre-wired modules to be connected to the proper pins on a back panel. These modular connectors also permit the quick connection of multi-wires in a cable to circuits on a printed circuit board or back panel.
Often times with complex circuitry, high-density contacts between cables and printed circuit boards make it difficult to make inner-connections between multi-wired cables and these printed circuit boards. Many times, the wire in the module has to be stretched or strained in order to make contact with the pins on a circuit board or back panel. Sometimes these wires are strained at a 90xc2x0 angle or greater. Over time this may cause the wire cable insulation to rip or tear apart and expose the live wire. Any exposure of live wire presents a safety hazard and may result in a short circuit. Additionally, when the wire is strained, the wire may disconnect from the back panel or circuit board.
Therefore, it is an object of the present invention to overcome these deficiencies by providing a modular connector strain relief back shell apparatus that provides wire strain relief.
The present invention is a modular connector strain relief back shell apparatus which may be used in connection with vehicle wiring systems. The modular connector strain relief back shell apparatus includes three sections, a first section, a second section, and a third section. The first section includes a housing having a first open side and a second open side. A plurality of wire-tie receiving orifices are defined adjacent the second open side of the housing. The second section includes a modular frame having a plurality of receiving sections. The modular frame is capable of being received within the housing. The third section includes at least one modular connector having a plurality of wire-receiving cavities for receiving wire. Each modular connector is capable of being received within the receiving section of the modular frame.
The housing includes a first wall, a second wall, a third wall, and a fourth wall. The walls have an inner surface and define a rectangular-shaped cavity. The plurality of wire-tie receiving orifices is defined on the first wall and the second wall of the housing. The housing also includes a plurality of protruding orifices for receiving fasteners. At least one protruding orifice is defined on the inner surface adjacent the third wall of the housing, and at least one protruding orifice is defined on the inner surface adjacent the fourth wall of the housing. Further, the housing includes a plurality of latch pins extending away from the cavity. At least one latch pin is defined on the first wall and at least one latch pin is defined on the second wall of the housing.
The modular frame includes a first open end, a second open end, a first frame wall, a second frame wall, a third frame wall , and a fourth frame wall. The frame walls have an inner surface and an outer surface. The inner surface of the frame walls define an interior cavity, and the third frame wall and the fourth frame wall define the plurality of receiving sections of the modular frame. Further, each receiving section of the modular frame includes a pair of tab-receiving slots, a pair of clip-receiving grooves, and a pair of longitudinal extending protrusions for guiding and securing the modular connector within the receiving section of the modular frame. The pair of tab-receiving slots further includes a first tab-receiving slot defined on the third frame wall adjacent the first open side of the modular frame and a second tab-receiving slot defined on the fourth frame wall adjacent the first open side of the modular frame. The pair of clip-receiving grooves further includes a first clip-receiving groove defined on the outer surface of the third frame wall and a second clip-receiving groove defined on the outer surface of the fourth frame wall. The pair of protrusions further includes a first protrusion defined on the inner surface of the third frame wall and a second protrusion defined on the inner surface of the fourth frame wall.
The modular frame also includes a first lip and a second lip. The first lip is defined on the first frame wall adjacent the second open end of the modular frame and extends radially outward away from the interior cavity. The second lip is defined on the second frame wall adjacent the second open end and extends radially outward away from the interior cavity. Further, the first lip and the second lip of the modular frame include a plurality of slots adapted to receive fasteners for securing the modular frame to the housing via the orifices in the housing.
The modular connector includes a body having a first side, a second side, a third side, and a fourth side. The plurality of wire-receiving cavities is defined on the body and extends from the first side to the second side of the body. The body further includes a pair of guide slits, a pair of clips, and a pair of tabs.
The pair of guide slits includes a first guide slit defined on the third side of the body and a second guide slit defined on the fourth side of the body. The guide slits are adapted to engage the protrusions in the receiving section of the modular frame. The pair of clips includes a first clip and a second clip. The first clip is defined on the third side of the body and extends axially in a direction toward the second side of the body. The second clip is defined on the fourth side of the body and extends axially in a direction toward the second side of the body. The clips are adapted to fasten into the clip-receiving grooves in the receiving section of the modular frame. The pair of tabs includes a first tab and a second tab. The first tab is defined on the third side of the body and extends axially in a direction toward the second side of the body. The second tab is defined on the fourth side of the body and extends axially in a direction toward the second side of the body. The tabs are adapted to be received by the tab-receiving slots in the receiving section of the modular frame.
The present invention is also a method of providing wire strain relief when using pre-wired modules for electrical wiring applications. The method includes the steps of providing a modular connector strain relief back shell apparatus as previously described. Secondly, a plurality of wires is inserted through the wire-receiving cavities of the modular connector. Thirdly, the modular connector is inserted into the modular frame. Fourthly, the modular frame is inserted into the housing. Finally, at least one wire within the wire-receiving cavity is fastened to the housing via a wire-tie inserted through at least two wire-tie receiving orifices and fastened around the wire.
The attachment of the wire to the housing provides wire strain relief to the wires in order to keep the wires from either disconnecting from the terminals and/or tearing the insulation on the wires thereby exposing the live wire.